So I have a Peavey Transtube 212 EFX that I've had for about 4 years or so. Recently at a party some drunk guy tried to run his amp head through the external speaker-out jack on my amp. It worked for about 2 seconds then sound just stopped. After I got the amp home I tried playing through the front of it, but couldn't get any sound. If I turn the volume up to max then I get a small amount of volume, but it's very tinny and has no backbone. I've taken out the preamp to check for overheat marks, but I can't find anything.

Can someone help me out and give me some advice?

First thing. Run the amp through a different speaker and run the speaker with a different amp. He may have just blown your speaker. If the speaker is good, look for any open fuses on the main pcb. A lot of things could have happened. The two most likely are a blown speaker and/or a blown output amp. Btw, that's was a really dumb thing for him to do.

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Stage Guitars: '80s Thin line LP Custom, '70 LP Standard, '83 Squier Black Headstock Strat w/ Dan Torres pickups, '59 Black Danelectro DC, sometimes others.

Pedal Board: Nady UHF 10 -> TU2 -> Rocktron Big Crush -> 70s MXR Phase 100 -> Cry Baby -> Bad Monkey -> Early '80s Rat -> Early '80s Ibanez CS 9 -> Ibanez DE 7 -> Behringer Dr 100 Stereo Reverb

Stage amps: '63 Blonde Tremolux w/ two original 2X10 cabinets with a '60 Ampeg Rocket/18 watt VTB Marshall clone/ Epi VJ into a Mashall 1965A

Yeah he was drunk. I tried using the external speaker jack to run through an extension cabinet, but it had the same effect. Does that rule out the speakers?

I also checked the fuses and they all look alright, but I'm no expert.

You need to disconnect the internal speaker and hook up another. It can be an extension cab, but you should hook it up as the internal speaker is connected. (alligator clip leads are good for this or a jack with spade lugs) The fuses must be checked with an ohm meter. Visual inspection will not tell you much.

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Stage Guitars: '80s Thin line LP Custom, '70 LP Standard, '83 Squier Black Headstock Strat w/ Dan Torres pickups, '59 Black Danelectro DC, sometimes others.

Pedal Board: Nady UHF 10 -> TU2 -> Rocktron Big Crush -> 70s MXR Phase 100 -> Cry Baby -> Bad Monkey -> Early '80s Rat -> Early '80s Ibanez CS 9 -> Ibanez DE 7 -> Behringer Dr 100 Stereo Reverb

Stage amps: '63 Blonde Tremolux w/ two original 2X10 cabinets with a '60 Ampeg Rocket/18 watt VTB Marshall clone/ Epi VJ into a Mashall 1965A

Mk. I figured as much about the fuses, but since I'm not working at a guitar shop anymore it's kinda slow-going getting all the gear I need to work from home.

I'll try your speaker suggestion tomorrow. I have several decent speakers lying around. Thanks for your help, I'll keep nagging this thread if that doesn't bring any results lol.